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jhgerber

Whats The Story With Star 129?

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The point remains that how any machine sees a diamond is totally irrelevant to how people see it.

To users of the BrillianceScope machine...isn't it true that by simply placing the diamond on the machine differently, you will get two totally different results?

Of course anyone that's put money into these things will try very hard to show how they are useful. I do not believe they are useful for consumers who actually want to know what the diamond looks like.

If sellers want to advise folks to buy blind, there's plenty of sites showing nothing but stats.

If sellers are advising people to go in with their eyes open, my feeling is that these machines give nothing usefull.

 

I hear what you’re saying David, but I think we all put money into what we believe in. That includes proportions scanners, structured setups for IS and ASET, and the time it takes to produce high quality photographs. We do this to showcase the high quality of our products and build consumer confidence.

 

BrillianceScope is different because it’s openly marketed as a tool to increase margins and sales. That and the ‘gadget’ factor turn some trade people off. You can’t deny that it has consumer appeal though... Those using it are simply investing in something they believe will achieve the consumer confidence others build in other ways.

 

What turns me off is the misinformation spread in the mainstream (that’s when it turns from the BrillianceScope into the “BS†:rolleyes: )… Store employees in commercial markets are capable of spreading epic bunk. That’s not restricted to any single issue of course - it makes it hard on all of us.

 

Tomato, tomahto, shaken, stirred… We can debate the technical merits ‘til we hear the chimes at midnight but we’re all in agreement that the eyes have it, and we hold true to the same fundamental values. There are a number of ways to represent top quality products and a little departure on this topic isn’t such a bad thing.

Edited by JohnQuixote

John Pollard

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Glad to see that the debate about the BrillianceScope is alive and well! I participated in those debates on another Diamond Forum in early 2002. Recently, I've returned to the diamond market again and not much has changed as far as the controversy surrounding this instrument. [in fact, I just made reference to those controversies on yet another Diamond Forum a couple of days ago and managed to get myself banned! :rolleyes: touchy stuff!].

 

I'm an amateur in diamonds but a professional in optics.

 

To me, there are obvious differences in IdealScope and BrillianceScope, even if they claim to measure the same thing. One is an analog instrument where the result is an image interpreted by my eye and brain, while the other is based on digital readings (which are converted to a qualitative scale for my interpretation). I have a basic intuitive understanding that complicated symmetry relationships must be satisfied to produce a nice hearts and arrows pattern. I can grasp that the absolute shade of red of the image doesn't matter, it's the relative shades that are important. I can get my mind around the idea that different combinations of angles can produce a nice hearts and arrows pattern if the facets are oriented correctly to one another.

 

The BrillianceScope is a much more complicated device than an IdealScope. I am assuming that it requires the accurate measurement of the light source intensity, in absolute quantities, and the measurement of light return with another detector, also in absolute quantities. The light sources and detectors I work with are periodically sent for calibration at NIST, thus they are NIST traceable. This is not the case with the IdealScope. Furthermore, these absolute measurements are somehow converted to a qualitative scale. In other words, they are not expressed in scientific radiometric or photometric units. And for the same reasons that cut types other than round brilliant can't be analyzed due to the relative position of the light sources and detectors, I can grasp the argument that slight different round cuts will respond better to the positioning of light sources and detectors in this instrument.

 

It's easy for me to imagine ways in which a BrillianceScope result could have error. It's a complicated instrument that tries to produce an easy to interpret result. The IdealScope is a very simple instrument producing a more complicated result. But for me, the overall result is one that is easier to grasp: it is a visual representation of the diamond's symmetry. It's impossible for me to imagine how one could "fake" an IdealScope image without switching out the diamond. While I'm not suggesting anyone is doing this with the BrillianceScope, because it is such a complicated instrument requiring calibration, I would have a lot more confidence in it if the GIA or AGS added BrillianceScope results to their reports, rather than the vendor.

 

my $0.02.

 

Diasurfer, thanks for your overview. The analog vs. digital is something I shouldn’t have forgotten to mention, especially since it goes to a fundamental distinction between these metrics:

 

1. Ideal-Scope & ASET are light-source independent. They show what angles the diamond will draw its light from and where the light is going, regardless of environment.

 

2. BrillianceScope, ISEE and Imagem are light-source dependent. They illuminate the diamond in one closed chamber and count pixels digitally (BrillianceScope does use several lighting schemes in its chamber; not sure about the others).

 

AGS and GIA considered using a light-source dependent approach in assessment but decided against it, primarily because a diamond will find itself in an infinite number of lighting conditions over a lifetime of wear. No single lighting scheme is sufficient. Even with large sampling, any digital evaluation relies on whatever ‘goodness measure’ the developer invented, and no one has agreed on what the technical aspects of a ‘goodness measure’ should be.

 

AGSL founded their research on angular spectrum (ASET) precisely because it is light-source independent. Regardless of environment, a diamond will draw its light from the same angles and either return, or not return it, to the viewer. It’s a great example of the elegance of simplicity.

 

Interestingly, in what some view as a shortcut to play catch-up with the ‘big boys,’ EGL-USA will be adding a light behavior grade to their reports this month using Imagem technology… It’s a development which puts them out-of-step with GIA & AGS philosophies.

 

PS: Glad to see someone familiar with the NIST.

Edited by JohnQuixote

John Pollard

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Interestingly, in what some view as a shortcut to play catch-up with the ‘big boys,’ EGL-USA will be adding a light behavior grade to their reports this month using Imagem technology… It’s a development which puts them out-of-step with GIA & AGS philosophies.

 

John, I was reading about the Imagem product the other day as well. When you say EGL-USA is out of step with GIA/AGS are you referring to the automated grading (color, clarity, etc) that the Imagem machine generates, thus eliminating human grading? Or is there some other reason? Do you know if they're using this in their new grading systems or just using this machine for light performance only? From what I understand even Imagem says that the machine is used to aid in measuring color/clarity however it is not supposed to substitute human grading and that a gemologist is still needed to verify the results.

 

Also do you know if EGL-USA will be offering the 360 light performance report for all fancy shapes? The Imagem is apparently capable of measuring diamonds of all shapes and sizes.

 

I've asked these questions but gotten no response yet from EGL-USA, just wondering if you heard anything.

 

Kind Regards,

Yosef


Yosef Adde

Adylon.com - Diamonds & Bridal Jewelry (Burbank, CA)

http://www.adylon.com

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Interestingly, in what some view as a shortcut to play catch-up with the ‘big boys,’ EGL-USA will be adding a light behavior grade to their reports this month using Imagem technology… It’s a development which puts them out-of-step with GIA & AGS philosophies.

 

John, I was reading about the Imagem product the other day as well. When you say EGL-USA is out of step with GIA/AGS are you referring to the automated grading (color, clarity, etc) that the Imagem machine generates, thus eliminating human grading? Or is there some other reason? Do you know if they're using this in their new grading systems or just using this machine for light performance only? From what I understand even Imagem says that the machine is used to aid in measuring color/clarity however it is not supposed to substitute human grading and that a gemologist is still needed to verify the results.

 

Also do you know if EGL-USA will be offering the 360 light performance report for all fancy shapes? The Imagem is apparently capable of measuring diamonds of all shapes and sizes.

 

I've asked these questions but gotten no response yet from EGL-USA, just wondering if you heard anything.

 

Kind Regards,

Yosef

 

Yosef, I don't know much: The 360 report has an overall grade for the diamond (called DNA or diamond natural attraction) with seven cut & proportion elements, two for finish and three for light behavior. I infer those will be the Imagem measures of “brilliance, sparkle and intensity†but I’m not sure about that (?) especially since Mitch Jakubovic was quoted as saying the new report accounts for the “fire and magic†of a stone...

 

That is weird since Imagem, in the past, has not included fire or dispersion in the measures they use (see the FAQ here)

http://www.imageminc.com/answers/ImaGemAnswers-LB.htm

 

Using a machine like Imagem is a departure from GIA/AGS philosophy because both of those labs tested and decided against light-source dependent measures like this (see my reply to Diasurfer above).

 

I’m passably familiar with Imagem's color/clarity grading. This isn’t entirely new technology, as there are spectrophotometers like the SAS2000 and rough planning scanners which do these things. I’m impressed with what Imagem has done to integrate them into a practical grading package though. With that said it’s still absolutely necessary to have human gemologists involved in the process. Personally I'm more interested in that aspect than the “light behavior†portion. The advances being made in clarity mapping are pretty remarkable.

Edited by JohnQuixote

John Pollard

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Using a machine like Imagem is a departure from GIA/AGS philosophy because both of those labs tested and decided against light-source dependent measures like this (see my reply to Diasurfer above).

 

I was under the impression AGS did use a light performance machine rather then just analyzing through an ASET and giving it a cut grade based on a human evaluation. I'm really not that familiar with AGS's process for light performance, when they fax you a copy of the results and ask you which report you want, some of their findings are accurate to 3 decimal places (if memory serves correct, I don't have the sheet infront of me), I assumed this was the result of some machine? If you could shed some light on how they grade the light performance and where the high precision comes from it I would appreciate it.

 

Thanks,

Yosef


Yosef Adde

Adylon.com - Diamonds & Bridal Jewelry (Burbank, CA)

http://www.adylon.com

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Anyone else's eyes hazing over with all this techno talk?

Leakage, light "performance"?

This is all so complicated.

 

Luckily, my education in grading diamonds has always been about the actual diamond.

Which, when you think about it- is a fairly simple thing.

 

You look at it, and can easily see what makes it good or bad.

 

Here's a good analogy- John- do you know the radius of the curve on the fender of a Boxster?

Of course not- you look, and you know you love the way that sucker looks.

 

Still, your point is well taken- there are consumers that believe in this stuff,

Consumers that are sold on this technology can find a lot of sellers promoting it.

 

My point, which bears repeating- is that evaluating actual diamonds is far more simple than that.

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Using a machine like Imagem is a departure from GIA/AGS philosophy because both of those labs tested and decided against light-source dependent measures like this (see my reply to Diasurfer above).

 

I was under the impression AGS did use a light performance machine rather then just analyzing through an ASET and giving it a cut grade based on a human evaluation. I'm really not that familiar with AGS's process for light performance, when they fax you a copy of the results and ask you which report you want, some of their findings are accurate to 3 decimal places (if memory serves correct, I don't have the sheet infront of me), I assumed this was the result of some machine? If you could shed some light on how they grade the light performance and where the high precision comes from it I would appreciate it.

 

Thanks,

Yosef

 

Sure Yosef. Humans correlation is always used, but the values for brightness, dispersion, leakage & contrast represent the diamond's potential for any environment, calculated via ray-tracing software that's light-source independent.

 

Here's how it works: The diamond is scanned and a 3D model is created. Ray-tracing reveals the diamond's angular spectrum (what you see in an ASET image), which shows where the diamond is drawing its light and where that light is going. This allows light return and dispersion postential to be calculated independent of environment. AGS uses 5 positions of the diamond relative to observer (straight and tilted to 4 compass points). All are measured at both 30 and 40 degrees of obstruction for a total of 10 slightly different positions/looks and sets of calculations.

 

Scan technology has only become precise enough to allow this in the last several years. That was my first reservation but I must admit what I've seen them put forward is the real deal. AGSL has a report they’ve introduced called a DQC which features a color image of the diamond’s ASET. I’ve browsed dozens of images and there is no perceivable difference between the scan-generated photo and the one seen you see in the analog ASET viewer in real life.


John Pollard

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Anyone else's eyes hazing over with all this techno talk?

Leakage, light "performance"?

This is all so complicated.

 

Luckily, my education in grading diamonds has always been about the actual diamond.

Which, when you think about it- is a fairly simple thing.

 

You look at it, and can easily see what makes it good or bad.

 

Here's a good analogy- John- do you know the radius of the curve on the fender of a Boxster?

Of course not- you look, and you know you love the way that sucker looks.

 

Still, your point is well taken- there are consumers that believe in this stuff,

Consumers that are sold on this technology can find a lot of sellers promoting it.

 

My point, which bears repeating- is that evaluating actual diamonds is far more simple than that.

 

You're right of course, I don't know. But I bet the guys at Porsche know, and probably the boys at Car & Driver who have analyzed windstream know as well. Do I need to know it? No. I need the wind in my hair, the leather at my back, that one-of-a-kind sound when you throttle-up and the tires hugging the road around corners. THAT'S how I evaluate it.

 

BUT, I bet there are some internet-savvy consumer-geeks out there who knows the relative XYZ of all that stuff and more. And if I were a Porsche dealer selling sight-unseen I'd expect to maybe answer those questions.

 

Point taken though, and a good reset. Plus you've inspired me. I need to pop out to do errands and will think of you as I drop the hammer on 4th gear... Without worrying about the radius of any curves except the one I'm cornering! :rolleyes:

Edited by JohnQuixote

John Pollard

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Sure Yosef. Humans correlation is always used, but the values for brightness, dispersion, leakage & contrast represent the diamond's potential for any environment, calculated via ray-tracing software that's light-source independent.

 

Here's how it works: The diamond is scanned and a 3D model is created. Ray-tracing reveals the diamond's angular spectrum (what you see in an ASET image), which shows where the diamond is drawing its light and where that light is going. This allows light return and dispersion postential to be calculated independent of environment. AGS uses 5 positions of the diamond relative to observer (straight and tilted to 4 compass points). All are measured at both 30 and 40 degrees of obstruction for a total of 10 slightly different positions/looks and sets of calculations.

 

Scan technology has only become precise enough to allow this in the last several years. That was my first reservation but I must admit what I've seen them put forward is the real deal. AGSL has a report they’ve introduced called a DQC which features a color image of the diamond’s ASET. I’ve browsed dozens of images and there is no perceivable difference between the scan-generated photo and the one seen you see in the analog ASET viewer in real life.

 

 

Hi John, I appreciate your explanation. I still want to make sure I'm understanding correctly...

 

Does the ray-tracing obtain measurements from 5 positions to form a 3D model that is then fed into software (something like DiaCalc?) where a theoretical light performance is then calculated?

 

Or does the ray-tracing return ASET spectrum plots from 5 positions that are then compared and analyzed to a computer database of other ASET spectrum plots through algorithms to determine which diamond in the database it most resembles and therefor what it's theoretical light performance is?

 

If it's the first scenario then how is this different then other attempts to determine "ideal" specs based on various measurement combination charts, etc? If the second, then I guess this begs the question how do they know which "master set" of ASET spectrum plots in their database is truly "ideal"? If I'm wrong on both I would appreciate any clarification :rolleyes: I guess I'm just trying to see where the "assumptions" and/or "error" in the system lie because if you're not measuring physical light return then you're basically calculating a theoretical performance based on comparisons and formulas of some set of data, right?

 

Thanks again :unsure:

 

Yosef

Edited by Adylon

Yosef Adde

Adylon.com - Diamonds & Bridal Jewelry (Burbank, CA)

http://www.adylon.com

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1. Ideal-Scope & ASET are light-source independent. They show what angles the diamond will draw its light from and where the light is going, regardless of environment.

 

Not exactly.

 

Quality and interpretation of Idealscope images vary according to the lighting environments, distance between camera and diamond, and type of camera used.

Edited by barry

Barry
www.exceldiamonds.com
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"if you're not measuring physical light return then you're basically calculating a theoretical performance based on comparisons and formulas of some set of data, right?"

 

Adylon;

 

You're absolutely right. Ray-tracing has its limitations.


Barry
www.exceldiamonds.com
@Exceldiamonds on Twitter

Excel Diamonds on Facebook

sales@exceldiamonds.com
1-866-829-8600
1-212-921-0635

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